U.S. patent number 11,058,871 [Application Number 15/639,125] was granted by the patent office on 2021-07-13 for manufacturing an electrode array for a stimulating medical device.
This patent grant is currently assigned to Cochlear Limited. The grantee listed for this patent is Cochlear Limited. Invention is credited to Fysh Dadd, Andy Ho, Shahram Manouchehri, Nicholas Charles Kendall Pawsey, Peter Schuller, Peter Raymond Sibary.
United States Patent |
11,058,871 |
Dadd , et al. |
July 13, 2021 |
Manufacturing an electrode array for a stimulating medical
device
Abstract
A method of forming an electrode array is disclosed, the method
comprising: forming an elongate comb structure comprising a
plurality of longitudinally-spaced electrode contacts extending
from and supported by a spine; electrically connecting each of a
plurality of electrically conductive pathways to a respective one
of the plurality of electrode contacts; placing the conductive
pathways adjacent the contacts; placing silicone over the
conductive pathways and contacts; curing the silicone so as to
substantially retain the longitudinal spacing between neighboring
contacts; and severing the spine from the plurality of electrode
contacts.
Inventors: |
Dadd; Fysh (Lane Cove,
AU), Ho; Andy (Tsuen Wan, HK), Manouchehri;
Shahram (Auburn, AU), Pawsey; Nicholas Charles
Kendall (North Ryde, AU), Schuller; Peter
(Turramurra, AU), Sibary; Peter Raymond (Luddenham,
AU) |
Applicant: |
Name |
City |
State |
Country |
Type |
Cochlear Limited |
N/A |
N/A |
N/A |
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Assignee: |
Cochlear Limited (Macquarie
University, AU)
|
Family
ID: |
1000005674265 |
Appl.
No.: |
15/639,125 |
Filed: |
June 30, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170361088 A1 |
Dec 21, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14622130 |
Feb 13, 2015 |
9694174 |
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12743369 |
Feb 17, 2015 |
8955211 |
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PCT/US2008/083794 |
Nov 17, 2008 |
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10581090 |
May 31, 2011 |
7950134 |
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PCT/AU2004/001726 |
Dec 8, 2004 |
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Foreign Application Priority Data
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Dec 8, 2003 [AU] |
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2003906787 |
Sep 16, 2004 [AU] |
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2004905355 |
Nov 16, 2007 [AU] |
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2007906282 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N
1/0541 (20130101); H01R 43/02 (20130101); Y10T
29/49005 (20150115); Y10T 29/49204 (20150115); Y10T
29/49002 (20150115); Y10T 29/49208 (20150115); Y10T
29/4921 (20150115); Y10T 29/49211 (20150115) |
Current International
Class: |
A61N
1/05 (20060101); H01R 43/02 (20060101) |
References Cited
[Referenced By]
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WO |
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Other References
International Search Report, International Application No.
PCT/US2008/083794, dated Jan. 22, 2009. cited by applicant .
International Preliminary Examination Report, International
Application No. PCT/US2008/083794, dated Nov. 10, 2009. cited by
applicant .
Written Opinion, International Application No. PCT/US2008/083794,
dated Jan. 22, 2009. cited by applicant .
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08850709.0, dated Feb. 4, 2011 (8 paqes). cited by applicant .
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cited by applicant .
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applicant .
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|
Primary Examiner: Trinh; Minh N
Attorney, Agent or Firm: Pilloff Passino & Cosenza LLP
Cosenza; Martin J.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a Continuation application of U.S.
patent application Ser. No. 14/622,130, filed Feb. 13, 2015, which
is a Divisional application of U.S. patent application Ser. No.
12/743,369, filed Aug. 26, 2010, which is a National Stage of
International Application No. PCT/US2008/083794, filed Nov. 17,
2008, which is a Continuation-in-part of U.S. patent application
Ser. No. 10/581,090, filed Feb. 16, 2007, which is a National Stage
of International Application No. PCT/AU2004/01726, filed Dec. 8,
2004. Additionally, this application claims foreign priority
benefit of Australia Application No. 2007906282, filed Nov. 16,
2007, Australia Application No. 2004905355, filed Sep. 16, 2004,
and Australia Application No. 2003906787, filed Dec. 8, 2003. Each
of these applications is hereby incorporated by reference herein in
their entirety.
Claims
What is claimed is:
1. An apparatus, comprising: a spine segment; and a toothed
segment, wherein the spine segment and toothed segment are part of
a monolithic component, and the monolithic component is an
electrically conductive biocompatible material.
2. The apparatus of claim 1, wherein: the toothed segment comprises
a plurality of teeth extending away from the spine segment and the
spine segment holds the teeth of the plurality of teeth relative to
one another.
3. The apparatus of claim 1, wherein: there are at least 5 teeth
making up the toothed segment.
4. The apparatus of claim 3, wherein: the length of the spine
segment is at least 260 times a thickness of the spine segment.
5. The apparatus of claim 3, wherein: the length of the spine
segment is at least two (2) orders of magnitude greater than a
thickness of the spine segment.
6. The apparatus of claim 3, wherein: the toothed segment has a
cross-section that has a U-shaped portion, which cross-section lies
on a plane normal to a longitudinal axis of the spine segment.
7. The apparatus of claim 3, wherein: the toothed segment includes
a plurality of teeth, respective teeth of the plurality of teeth
have a width that is greater than a thickness, the width being
measured in a direction of a longitudinal axis of the spine
segment, and the thickness being normal to the width and the width
is less than respective heights of the respective teeth.
8. The apparatus of claim 3, wherein: the toothed segment includes
a plurality of teeth, all teeth of the apparatus are arrayed in a
single line along a length of extension of the spine segment.
9. The apparatus of claim 3, wherein: the spine segment and toothed
segment form an elongate comb.
10. The apparatus of claim 1, further comprising: a wired segment,
wherein the wired segment is not monolithic with the monolithic
component.
11. The apparatus of claim 1, further comprising: a wired portion,
wherein the wired portion comprises a plurality of wires, the wires
of the plurality of wires being respectively connected to
respective teeth of the toothed section.
12. The apparatus of claim 11, further comprising: a silicone body
in which respective first portions of respective teeth of the
toothed section are located, wherein the spine segment is outside
of the silicone body.
13. The apparatus of claim 12, wherein: the silicone body, the
monolithic component and the wired portion form an embryonic
electrode array of a cochlear implant.
14. The apparatus of claim 12, wherein: the apparatus is part of an
embryonic electrode assembly that consists of the silicone body,
the monolithic component and the wired portion.
15. The apparatus of claim 11, wherein: the teeth of the toothed
portion are concavely bent and the spine is flat.
16. The apparatus of claim 15, wherein: the wires are located on
the concave sides of the teeth.
17. The apparatus of claim 1, wherein: the spine segment and the
toothed segment collectively are in a shape of a rake.
18. The apparatus of claim 1, wherein: the spine segment and the
toothed segment collectively form a comb.
19. The apparatus of claim 1, wherein: in a direction of a
longitudinal axis of the monolithic component, the distance between
respective teeth of the toothed segment is approximately 0.3 mm and
a width of the teeth is at least about the same.
20. An assembly, comprising: a spine segment; a toothed segment; a
wired portion, wherein the wired portion comprises a plurality of
wires, the wires of the plurality of wires being respectively
connected to respective teeth of the toothed section; and a
silicone body in which respective first portions of respective
teeth of the toothed section are located, wherein the spine segment
is outside of the silicone body, wherein the spine segment and
toothed segment are part of a monolithic component, the monolithic
component is an electrically conductive biocompatible material, and
the assembly consists of the silicone body, the monolithic
component and the wired portion.
Description
BACKGROUND
The present invention relates generally to implantable electrodes,
and more particularly, to an electrode array for use in medical
implants.
RELATED ART
There are a variety of medical implants that deliver electrical
stimulation to a patient or recipient ("recipient" herein) for a
variety of therapeutic benefits. For example, the hair cells of the
cochlea of a normal healthy ear convert acoustic signals into nerve
impulses. People who are profoundly deaf due to the absence or
destruction of cochlea hair cells are unable to derive suitable
benefit from conventional hearing aid devices. A type of prosthetic
hearing implant system commonly referred to as a cochlear implant
has been developed to provide such persons with the ability to
perceive sound. A cochlear implant bypasses the hair cells in the
cochlea to directly deliver electrical stimulation to auditory
nerve fibers, thereby allowing the brain to perceive a hearing
sensation resembling the natural hearing sensation.
The electrodes utilized in stimulating medical implants vary
according to the device and tissue which is to be stimulated. For
example, the cochlea is tonotopically mapped and partitioned into
regions, with each region being responsive to stimulus signals in a
particular frequency range. To accommodate this property of the
cochlea, cochlear implants typically include an array of electrodes
each constructed and arranged to deliver an appropriate stimulating
signal to a particular region of the cochlea.
SUMMARY
In accordance with one embodiment of the present invention, a
method of forming an electrode array is disclosed, the method
comprising: forming an elongate comb structure comprising a
plurality of longitudinally-spaced electrode contacts extending
from and supported by a spine; electrically connecting a plurality
of electrically conductive pathways to the plurality of electrode
contacts; constraining the plurality of contacts to substantially
retain the longitudinal spacing between neighboring contacts; and
severing the electrode contacts from the spine.
In accordance with another embodiment of the present invention, a
method of forming an electrode array is disclosed, the method
comprising: forming an elongate comb structure comprising a
plurality of longitudinally-spaced electrode contacts extending
from and supported by a spine; electrically connecting each of a
plurality of electrically conductive pathways to a respective one
of the plurality of electrode contacts; placing the conductive
pathways adjacent the contacts; placing silicone over the
conductive pathways and contacts; curing the silicone so as to
substantially retain the longitudinal spacing between neighboring
contacts; and severing the spine from the plurality of electrode
contacts.
BRIEF DESCRIPTION OF THE DRAWINGS
Aspects and embodiments of the present invention are described
herein with reference to the accompanying drawings, in which:
FIG. 1A is a perspective view of an exemplary medical device, a
cochlear implant, having an electrode assembly which may be
advantageously manufactured using embodiments of the present
invention;
FIG. 1B is a side view of the implantable components of the
cochlear implant illustrated in FIG. 1A;
FIG. 2 is a side view of an embodiment of the electrode array
illustrated in FIGS. 1A and 1B in a curled orientation;
FIG. 3 is a schematic view of the electrode array of FIG. 2 in situ
in a cochlea;
FIG. 4 is a perspective view of intermediate manufacturing product,
a comb, which may be used during manufacture of an electrode array
in accordance with embodiments of the present invention;
FIG. 5 is a perspective magnified view of a portion of the comb
illustrated in FIG. 4;
FIG. 6 is a side view of an individual electrode contact on the
comb illustrated in FIG. 5, in accordance with embodiments of the
present invention;
FIG. 7 is a side view of the electrode contact illustrated in FIG.
6 with conductive pathways in the form of wires shown positioned in
the trough of the contact;
FIG. 8 is a top view of an intermediate manufactured product
showing a cut line for removing the spine from the teeth of the
comb, in accordance with embodiments of the present invention;
FIG. 9 is a flowchart of a method of making the comb of FIG. 4, in
accordance with embodiments of the present invention;
FIG. 10 is a flowchart of a method of making an electrode assembly
shown in FIGS. 1-3, using the comb of FIG. 4, in accordance with
embodiments of the present invention;
FIG. 11 shows an alternative electrode contact configuration with a
V-notch;
FIG. 12 shows an alternative configuration for the comb illustrated
in FIGS. 4 and 5;
FIG. 13 shows an alternative configuration for the comb illustrated
in FIGS. 4 and 5;
FIG. 14 shows an alternative configuration for the comb illustrated
in FIGS. 4 and 5;
FIG. 15 shows an alternative configuration for the comb illustrated
in FIGS. 4 and 5; and
FIG. 16 shows an arrangement of two combs on sheet of electrically
conductive material, in accordance with embodiments of the present
invention.
DETAILED DESCRIPTION
Embodiments of the present invention are described herein primarily
in connection with one type of hearing prosthesis, namely a
cochlear implant. Cochlear implants generally refer to hearing
prostheses that deliver electrical stimulation to the cochlea of a
recipient. As used herein, the term "cochlear implant" also include
hearing prostheses that deliver electrical stimulation in
combination with other types of stimulation, such as acoustic or
mechanical stimulation. It would be appreciated that embodiments of
the present invention may be implemented in any cochlear implant or
other hearing prosthesis now known or later developed, including
auditory brain stimulators, or implantable hearing prostheses that
also acoustically or mechanically stimulate components of the
recipient's middle or inner ear.
FIG. 1A is a perspective view of an exemplary medical device having
an electrode carrier member manufactured in accordance with the
teachings of the present invention. Specifically, FIG. 1A is
perspective view of a cochlear implant 100 implanted in a recipient
having an outer ear 101, a middle ear 105 and an inner ear 107.
Components of outer ear 101, middle ear 105 and inner ear 107 are
described below, followed by a description of cochlear implant
100.
In a fully functional ear, outer ear 101 comprises an auricle 110
and an ear canal 102. An acoustic pressure or sound wave 103 is
collected by auricle 110 and channeled into and through ear canal
102. Disposed across the distal end of ear cannel 102 is a tympanic
membrane 104 which vibrates in response to sound wave 103. This
vibration is coupled to oval window or fenestra ovalis 112 through
three bones of middle ear 105, collectively referred to as the
ossicles 106 and comprising the malleus 108, the incus 109 and the
stapes 111. Bones 108, 109 and 111 of middle ear 105 serve to
filter and amplify sound wave 103, causing oval window 112 to
articulate, or vibrate in response to vibration of tympanic
membrane 104. This vibration sets up waves of fluid motion of the
perilymph within cochlea 140. Such fluid motion, in turn, activates
tiny hair cells (not shown) inside of cochlea 140. Activation of
the hair cells causes appropriate nerve impulses to be generated
and transferred through the spiral ganglion cells (not shown) and
auditory nerve 114 to the brain (also not shown) where they are
perceived as sound.
Cochlear implant 100 comprises an external component 142 which is
directly or indirectly attached to the body of the recipient, and
an internal component 144 which is temporarily or permanently
implanted in the recipient. External component 142 typically
comprises one or more sound input elements, such as microphone 124,
for detecting sound, a sound processing unit 126, a power source
(not shown), and an external transmitter unit 128. External
transmitter unit 128 comprises an external coil 130 and,
preferably, a magnet (not shown) fixed relative to external coil
130. Sound processing unit 126 processes the output of microphone
124 that is positioned, in the depicted embodiment, by auricle 110
of the recipient. Sound processing unit 126 generates encoded
signals, sometimes referred to herein as encoded data signals,
which are provided to external transmitter unit 128 via a cable
(not shown).
Internal component 144 comprises an internal receiver unit 132, a
stimulator unit 120, and an elongate electrode assembly 118, also
referred to as a lead. Internal receiver unit 132 comprises an
internal coil 136, and preferably, a magnet (also not shown) fixed
relative to the internal coil. Internal receiver unit 132 and
stimulator unit 120 are hermetically sealed within a biocompatible
housing, and are sometimes collectively referred to as a
stimulator/receiver unit. The internal coil receives power and
stimulation data from external coil 130, as noted above. Elongate
electrode assembly 118 has a proximal end connected to stimulator
unit 120, and a distal end implanted in cochlea 140. Electrode
assembly 118 extends from stimulator unit 120 to cochlea 140
through mastoid bone 119. As described below, electrode assembly
118 is implanted in cochlea 140. In some embodiments electrode
assembly 118 may be implanted at least in basal region 116, and
sometimes further. For example, electrode assembly 118 may extend
towards apical region, or apex, 134 of cochlea 140. In certain
circumstances, electrode assembly 118 may be inserted into cochlea
140 via a cochleostomy 122. In other circumstances, a cochleostomy
may be formed through round window 121, oval window 112, the
promontory 123 or through an apical turn 147 of cochlea 140.
Electrode assembly 118 comprises a plurality of longitudinally
aligned and distally extending electrodes 148 disposed along a
length thereof. In most practical applications, electrodes 148 are
integrated into electrode assembly 118. As such, electrodes 148 are
referred to herein as being disposed in electrode assembly 118.
Stimulator unit 120 generates stimulation signals which are applied
by electrodes 148 to cochlea 140, thereby stimulating auditory
nerve 114.
In cochlear implant 100, external coil 130 transmits electrical
signals (i.e., power and stimulation data) to internal coil 136 via
a radio frequency (RF) link. Internal coil 136 is typically a wire
antenna coil comprised of multiple turns of electrically insulated
single-strand or multi-strand platinum or gold wire. The electrical
insulation of internal coil 136 is provided by a flexible silicone
molding. In use, implantable receiver unit 132 may be positioned in
a recess of the temporal bone adjacent auricle 110 of the
recipient.
While various aspects of the present invention are described with
reference to a cochlear implant, it will be understood that various
aspects of the present invention are equally applicable to other
stimulating medical devices having an array of electrical
simulating electrodes such as auditory brain implant (ABI),
functional electrical stimulation (FES), spinal cord stimulation
(SCS), penetrating ABI electrodes (PABI), and so on. Further, it
should be appreciated that the present invention is applicable to
stimulating medical devices having electrical stimulating
electrodes of all typessuch as straight electrodes, peri-modiolar
electrodes and short/basilar electrodes.
Throughout this description, the term "electrode array" means a
collection of two or more electrodes, sometimes referred to as
electrode contacts or simply contacts herein. The term "electrode
array" also refers to or includes the portion of the carrier member
in which the electrodes are disposed. It should be appreciated that
in the literature and prior art the term "electrode array" refers
to both, the electrodes as well as the combination of electrodes
and the carrier member in which the electrodes are disposed.
FIG. 1B is a side view of an internal component 144 of a
conventional cochlear implant. Internal component 144 comprises a
receiver/stimulator 180 and an electrode assembly or lead 118.
Electrode assembly 118 includes a helix region 182, a transition
region 184, a proximal region 186, and an intra-cochlear region
188. Proximal region 186 and intra-cochlear region 188 form an
electrode array 190. Electrode array 190, and in particular,
intra-cochlear region 188 of electrode array 190, supports a
plurality of electrode contacts 149. These electrode contacts 148
are each connected to a respective conductive pathway, such as
wires, PCB traces, etc. (not shown) which are connected through
lead 118 to receiver/stimulator 180, through which respective
stimulating electrical signals for each electrode contact 148
travel.
FIG. 2 is a side view of electrode array 190 in a curled
orientation, as it would be when in situ in a patient's cochlea,
with electrode contacts 148 located on the inside of the curve.
FIG. 3 shows the electrode array of FIG. 2 in situ in a patient's
cochlea 140. In this exemplary application, electrode contacts 148
are shown in electrical contact with the tissue to be stimulated,
as will be understood by those skilled in the art.
FIG. 4 is a perspective view of an intermediate product 400 made
during manufacture of an electrode array 190 in accordance with
embodiments of the present invention. As shown in FIG. 4, electrode
contacts 148 are formed from the unitary piece 400 of electrically
conductive material, referred to herein as a "comb" 400. Comb 400
includes a number of teeth 404 extending from and supported by a
spine 402. In the example shown, there are twenty-two
teeth/electrode contacts 404 extending from an elongate spine 402.
In practice, there may be any number of electrode contacts, ranging
from 2 to 256 electrode contacts, or more. This may, for example,
include 3, 4, 5, 6, 7, 8, 9, 10, 10-20, 20-30, 30-50, 50-100,
100-150, 150-200, 200-256, 256-300 electrode contacts, etc.
Electrode contacts 148 are preferably made from platinum, but any
other suitable material such as iridium, a platinum/iridium alloy,
or other platinum or iridium alloy may be used, as will be
understood by one of ordinary skill in the art.
For certain applications, electrode contacts 148 are preferably
formed in a U-shape, as shown in FIGS. 5 and 6. FIG. 5 is a
magnified view of a portion of comb 400; FIG. 6 is a side view of
an individual electrode contact 148 on comb 400. At this stage of
manufacture, electrodes 148 are in the form of teeth of comb 400.
As shown in FIG. 6, teeth 404 have a relatively large exposed
surface area. Electrode array 190 is particularly adapted to bend
and flex in one direction, making it well-suited to inserting into
a curved body cavity, such as cochlea 50.
Preferably, the width of each tooth 404 of comb 400 is 0.3 mm and
the gap between them is approximately 0.3 mm. The total length of
such a comb is approximately 13 mm, based upon the preferred number
of teeth 404. Of course, these dimensions may be varied as required
by the particular design and application.
FIG. 5 also shows conductive pathways (in this example wires) 502
connected to respective teeth 404. The method of connection may be
done in any suitable manner such as welding, as will be described
in more detail below. FIG. 7 is a side view of a tooth/contact 148
showing the collection of conductive wires 502 being supported in
the trough of one of the U-shaped teeth 404. Once wires 502 have
been connected to electrode contacts 148, electrode contacts 148
are cut off or otherwise severed from spine 402. The cut point is
preferably just below spine 402 so that contacts 148 are of a
substantially rectangular shape, as shown in FIG. 8.
Spine 402 of comb 400 serves a dual function. Firstly, spine 402
connects electrode contacts 148 so that the contacts are in one
piece and thus in a fixed location relative to each other.
Secondly, spine 402 provides a secure holding point to secure comb
400 to the welding jig (not shown), thus holding electrode contacts
3 during subsequent processing operations.
A method of forming the comb 400 is described below with reference
to FIG. 9. At step 902, a platinum sheet having a thickness of, for
example, 50 um, is worked (in this example, punched) to provide the
shape of comb 400 as shown in FIG. 8. Of course other methods may
be used to form comb 400, such as EDM to micromachine the combs. It
is envisaged that in certain applications smaller contacts will be
desired and once the limitations of punching electrodes has been
reached they could be cut out using a laser and subsequently formed
using the methods described above or out using a laser and formed
using laser ablation.
Rotary knife tooling could also be used to cut a platinum sheet, or
other materials, into electrode contacts with a spine or with an
adhesive backing where the rotary blades cut through the first
layer leaving the spine intact, and following forming, welding,
molding etc. the second layer can be peeled off. Various other
techniques for punching, cutting, and otherwise working the sheet
are also described in International Patent Publication No. WO
02/089907.
In step 904, the planar comb is formed into its 3-dimensional shape
as shown in FIGS. 4 and 5 by forming a U-shape in teeth 804. In
step 906, the shaped comb is washed in preparation for welding. It
is possible to form a plurality of combs from a single sheet of
material. For example, about 25 combs can be formed
quasi-simultaneously from a platinum strip 500 mm in length via a
pneumatic press.
The method of forming electrodes 148 from the formed comb 400 is
described with reference to FIG. 10. At step 1002, the finished
three-dimensional comb 400 is placed into a welding jig (not shown)
ready for wires 32 to be joined to the comb. The comb 400 is
secured by being held along the length of the spine 31, thereby
providing a secure hold.
At step 1004, a wire 32 is welded to the most proximal electrode
contact 148. At step 1006, an amount (for example a droplet) of
silicone is placed in the trough of the electrode contact 148. In
step 1008, a second wire 502 is welded to the second most proximal
electrode contact 148. At step 1010, the wire from the second
contact is bedded down into the silicone droplet in the trough of
the first electrode. In step 1012, a droplet of silicone is placed
in the trough of the second electrode contact. In step 1014, steps
1002 through 1012 are repeated until all wires 502 have been
connected to their respective electrode contacts 148. As one of
ordinary skill in the art would appreciate, the sequence of placing
the wires and silicone may be different in alternative embodiments
of the present invention. Similarly, it should be appreciated that
each wire, or all wires, may be placed in the electrode troughs in
a single operation followed by the application of silicone to none,
some or all of such troughs.
After all wires have been connected, a production stylet (for
example, a PTFE coated wire) is suspended above or otherwise placed
on top of the wires in step 1016. This stylet is removed later and
forms the lumen of lead. In step 608, silicone is placed above each
contact over the production stylet, to form a sub-assembly, and the
silicone is cured in an oven in step 1020. At this point in the
process the electrode contacts 148 are substantially constrained in
a relative longitudinal position thereby substantially retaining
the longitudinal spacing between neighboring contacts.
In step 1022, the sub-assembly is removed from the welding jig. In
step 1024, spine 402 is then severed such as by cutting from comb
400 to leave the individual electrode contacts 148. In alternative
embodiments, a V-notch 1102 is formed in teeth 148 to facilitate
separation of the teeth from spine 402 simply by "snapping off" the
teeth, as shown in FIG. 11. Alternatively, the separation of teeth
804 from spine 402 may be facilitated by forming a part of the
teeth 804 with a narrower part such as shown in FIG. 12. This
provides an alternative "snapping" option.
It is also possible to change the order of some of the steps above.
For example, the step 501 of forming the comb into a 3-dimensional
shape may be performed after the steps of welding the conductive
wires 32 into place. Performing the steps in other sequences is
also contemplated. It is also possible to connect 2 or more wires
to one or more electrodes. This may provide an advantage of
redundancy and may increase the robustness of the resulting lead
20.
The process continues as is known in the art. In particular, one
method of molding of electrode array is as described in U.S. Pat.
No. 6,421,569, the disclosure of which is incorporated by
reference.
The sub-assembly is preferably carefully curved to match the shape
of a curved molding die (not shown). The assembly is then placed in
the curved molding die with the contacts being located closer to
the medial side (inside of the curve). The space in the die is
packed with silicone material. A matching die cover is placed over
the assembly and pressed down. The die is then placed in an oven to
cure the silicone. The die is then open to allow the resulting
electrode array to be removed from the die.
The electrode array described above forms the distal end of lead
assembly 20 that is adapted to be connected to implantable
receiver/stimulator 10 (FIG. 1). Receiver/stimulator 10 is
typically housed within a metallic case. In one application,
receiver/stimulator 10 has an array of feed through terminals
corresponding to its multiple channels.
The electrode array facilitates the use of non-flat surface
finishes. For example, dimpled, corrugated, pitted or irregular
geometric shapes may be provided on the surface of electrode
contacts 30. These varied surface finishes may be achieved by
stamping a pattern finish in the punching and pre-forming
operation. Alternatively, the contact areas may be roughened by
controlled sandblasting of the array before or after molding.
Surface modification may also be achieved using laser ablation via
the direct write method or using a mask at almost any stage during
the manufacture of the electrode. A non-flat surface area may have
the advantage of increasing the effective size of the electrode
contact without requiring a larger electrode contact. This allows
smaller electrode contacts with equivalent surface areas to be
utilized. Various methods of creating such surface finishes are
described in for example, U.S. Pat. No. 4,602,637 and PCT
Application No. PCT/US2006/036966 (WO2007/050212)
Alternatively, the electrode contacts may be substantially planar
rather than U-shaped as described above. In this embodiment, comb
400 may be punched rather than formed. Such embodiments provide for
a relatively simpler manufacturing processing. In alternative
embodiments, electrode contacts 30 have a shape other than
rectangular, such as square, circular, triangular or oval.
In yet another alternative, the various aspects of the present
invention may be used to provide electrode arrays with a variable
pitch. Such constructions are disclosed in U.S. Pat. No. 7,184,843.
For example, comb 400 can be formed with teeth 404 having a
variable spacing, with the distal electrode contacts lying closer
together than the proximal ones. Other variations on the spacing
between electrode contacts may also be utilized.
In yet another alternative, a stepped sheet of a varying thickness
can be used to create comb 400 with spine 402, as shown in FIG. 13.
This has the advantage of increasing the torsional stability of
teeth/electrode contacts 404 while maintaining a relatively
consistent contact thickness.
In yet another alternative, spine 402 runs between electrode
contacts 404, as shown in FIG. 14.
In alternative embodiments, comb 300 may be formed to have a
substantially cylindrical shape as shown in FIG. 15. In one such
embodiment, electrode contacts 404 are circular with both ends
connected to spine 402. In manufacturing such a structure, teeth
404 may be rolled into shape, or alternatively, they may be formed
by etching the shape from a continuous platinum tube.
In yet another embodiment, two separate (not connected) spines 31,
31' hold two sets of respective electrode contacts 30, 30' as shown
in FIG. 16.
In yet another alternative, two or more arrays may be formed and
laminated together to form a single tissue stimulating electrode
assembly. For example, such an assembly might be formed from a
first lamination having seven electrodes, a second lamination
having eight electrodes, and a third lamination having eight
electrodes, to form an electrode assembly having 23 electrodes. In
the case of a cochlear electrode array, the formed array may have
22 intracochlear electrodes and one extracochlear electrode. Such a
lamination process would preferably result in a linear array of the
22 electrodes. Other combinations of layers, and other quantities
of electrodes in each layer, may be utilized to form arrays of
different lengths.
In the descriptions above, the electrically conductive pathways may
be provided by any suitable means including wires, conductive
deposits, conductive tracks, and the like.
The above and other embodiments of forming electrode arrays, and
the electrode arrays themselves, may provide one or more advantages
over conventional methods. Such advantages may include, and are not
limited to the following: they may be manufactured using easy, low
cost technology; they have lower parts count (for 22 electrode
contacts, the parts count has reduced by 21); they have higher a
Manufacturing Yield Rate (fewer problems during holding contacts
during at least welding); and they enable greater accuracy and
consistency with contact placement.
While various embodiments of the present invention have been
described above, it should be understood that they have been
presented by way of example only, and not limitation. It will be
apparent to persons skilled in the relevant art that various
changes in form and detail can be made therein without departing
from the spirit and scope of the invention. Thus, the breadth and
scope of the present invention should not be limited by any of the
above-described exemplary embodiments, but should be defined only
in accordance with the following claims and their equivalents.
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